Automatic interlocking drive clutch for can-making and other machines



S. STUART AUTOMATIC INTERLOCKING DRIVE CLUTCH FOR CAN MAKING AND OTHER MACHINES Filed Feb- 4, 1925 9 Sheets-Sht 1 SYDNEY STUART I .1 TOR his Attorney Dec. 7 1926. v

' s. STUART AUTOMATIC INTERLOCKING DRIVE CLUTCH FOR CAN MAKING AND OTHER MACHINES Ffilqd Feb- 4, 1925' 9 Sheets-Sheet 2 a j o /l/l/AIW //A his At torney Dec 7 S. STUART AUTOMATIC INTERLOCKING DRIVE CLUTCH F OR CAN MAKING AND OTHER MACHINES File Feb- 4,' 1925 9 Sheets-Sheet 5 SYDNEY STUART NTOR By L his Attorney Dec. 7 1926. v

s. STUART AUTOMATIC INTERLOCKING DRIVE CLUTCH FOR CAN MAKING ANDUTHER MACHINES Filed Feb. 4,. 1925 9 Sheets-Sheet 4 4 s orm smvm NTOR Y his Attorney Dec. 7,1926. 1,609,326 r s. STUART AUTOMATIC INPERLOCKING DRIVE CLUTCH FOB CAN MAKING AND OTHER MACHINES Filed Feb. 4, 1925 9 Sheets-Sheet 5 igunn SYDNEY STUART I JNTOR By Me.

his Attorney Dec. 7,1926. 1,609,326

I S. STUART AUTOMATIC INTERLOCKING DRIVE CLUTCH FOR CAN MAKING AND OTHER MACHINES Filed Feb.'4, 1925 9 Sheets-Sheet a his Attorney Dec. 7, 1926. 1,609,326

S- STUART AUTOMATIC INTERLOCKING DRIVE CLUTCH FOR CAN MAKING AND OTHER MACHINES ile f b- 4, 1925 9 Sheets-Shet 7 SYDNEY STUART his Attorney.

Dec. 7 1926.

. s. sTuART AUTOMATIC INTERLOCKING DRIVE CLUTCH FOR CAN MAKING AND OTHER MACHINES 9 Sheeis-Sheef. 8

Filed Feb. 4, 1925 SYDNEY STUART NVENTOR Dec. 7 1926.

8. STUART AUTOMATIC INZERLOGKING DRIVE CLUTCH FOR CAN MAKING AND OTHER MACHINES Filed Feb. 4, 1925 SYDNEY STUART.

warren his Attorney mm ww Patented Dec. 7, 1926.

SYDNEY STUART, OF LEICHHARDT, NEAR BYDNEY, NEW SOUTH WALES, AUSTRALIA,

ASSIGNGR TO JOHN HEINE & SON LIMITED, 0F LEICHHABDT, NEAR SYDNEY, AUS- TRALIA, A REGISTERED COMPANY.

AUTOMATIC INTERLOCKING DRIVE CLUTCH FOR. CAN-MAKING AND OTHER MACHINES.

Application filed February 4, 1925. Serial No. 6,760, and in Australia November 14, 1924.

This invention relates to interlocking clutches usable in machines for making sheet metal cans, machines for charging cans or other vessels with product to be enclosed therein, machines for applying sealing solution to cans, and machines for other purposes.

Can making machines include mechanism for feeding in formed can bodies one by one, "and in timing therewith feeding in formed caps one by one and for bringing the bodies and the caps .to other elements in the machine in which the caps are seamed to'the body ends. Can filling machines include an element for bringing the cans successively to a filling spout and dwelling or retarding their movement momentarily whilst they are passing under the spout in order to allow adequate time for the filling operation. Many other machines include two distinct mechanical elements'which must be arranged and controlled so as to function in cooperation. In all such machines now known, certain operating difiiculties: arise when one of the elements functions irregularly, and the object of the present invention is to provide automatic drive clutch controlling means for-ensuring mechanical coordination of two elements in a machine so that if one of them ceases to function the functioning of the other one will be arrested until the former resumes operation. For example in the case of a can capping machine the invention provides means whereby the feed of caps is arrested or in the case of filling machines whereby the fillingis arrested) when there occurs a break in the continuity of supply of bodies, or conversely to arrest the operation of the body feeder when there is interruption in the feed of caps. The invention will be described as embodied in a can body capping machine, and its applicability to other machines wil) be understood from that description.

The automatic clutch control means operate to arrest the movement of the lid supply element only whilst a miss occurs in the feed of bodies, and conversely to arrest the supply of bodies only whilst a miss occurs in the teed of caps. Similarly in the case of filling machines these means operate to arrest the delivery of product when a can is missing from the train of cans passing through the machine butto re-establish the I delivery as soonas regular supply of cans through the machine is reestablished. In any of these cases if the supply of bodies or of caps respectively should run out,'the

only one or more bodies or caps respectively 1 are missing from the trains of bodies and caps passing through the respective feed elements of the machine, the movement of the full element will be arrested until the de ficient element has made one or more partial movements and normal supply of feed I through itis re established, whereupon both elements will again be brought into operation simultaneously. So also in the case of filling machines the supply of product will be recommenced automaticallyafter a miss in the feed of cans as soon as a can comes to place. to receive the product from the delivery spout. r

The invention consists essentially in fitting trigger arms in the path of movement of the can bodies and can caps or either of them (or in the case of other machines, in

the path of movement of other articles),

utilizing the movement of these triggers, which occurs when the caps or bodies respectively trip them when passing them in the race, tocause the engagement of a clutch in the feed driving mechanism of the other element, and conversely, whenthe trig gers or either of them remain inoperative automatically holding the clutch open so that. operation of the element whose movement is required to be arrested Will no longer be possible for the reason that drive is not transmitted to it until normal feed through the unsupplled element has been restored.

The invention is therefore independent of the particular type of machine in which it may be embodied, provided, however, that it includes as part of its structure feed mechanism in which the cans and the caps (or other articles) are brought into the ma chine through independent feeders.

In can capping machines embodying the invention which I have constructed, the feeder devices are of a known type comprising rotary tables with means for taking formed caps from a stack at timed intervals and feeding them one by one into the machine, and for receiving formed open can bodies and feeding them synchronously with the caps into the machine in which subsequently the caps are fixed on the bodies.

The accompanying drawings illustrate only those parts of a can capping machine which are necessary for the explaining of the invention,

Fig. 1 is a top plan view of the body and cap feeder mechanism;

F 2 is a vertical section on the plane Fig. 1; i

Fig. is a vertical section on the plane 3-3 Fig. 1;

Fig. 1 is a perspective view of the inter-.- loclzing clutch mechanism which is controlled. by trigger arm movement;

Fig. 5 isan enlarged fragmentary vertical sectionv onthe plane 5*5 Fig. i;

Fig. 6 is a fragmentary sectional elevationalview. explanatory of the operationof theclutch iock and trigger controlling mechanism; this. detail refers to the parts illustrated in the upper portion of Fig. 4;

Fig. 718a horizontal section on the plane 7-7 Fig. 5;

Fig. dis a fragmentary plan. and horizontalfsection of the clutch in engaged position;

Fig, 9 is a fragmentary.:elevational viewtaken from the position 9-4) Fig. 7;

Fig. 10 1s a vertical section s mllar to Fig.

Fig. 5 shows the clutch engaged (see also 1 Fig. 8), whilst Fig. 10 shows the clutch disengaged (see also Fig. 13)

Fig. 11 is a fragmentary vertical section through the clutchshowingit disengaged (see also Fig. 10) and I Fig. 12 is a horizontal section on the plane 12-12 Fig. 11.;

Fig. 13 is a view similar to Fig. 8 showing the ciutch disengaged. .The drawings numbered. Figs. 1 to 13 re fer to the arrangement in:v which. the clutch control, is arranged for arresting the feed of caps whilstthere is an interruption, in. the supply of. can bodies. The following figures show substantially the same mechanical parts in an adapted arrangementin whichv the feed of bodies is arrested whilst the regular supply of caps is interrupted- It is to ac understood that both. these: mechanisms may be fitted on: one'machine so as to obtain complete interlocking of the feeders by arresting the motion of either feed element of it whenever any interruption occurs inthe continuity of the feed; in the other element of 1t;

Fig. Lit is atop plan of the feeder mechae Fig. 16 's vertical section, on the-plane Fig. 17 is a perspective elevational View showing the trigger controlled clutch interlocking mechanism; and

Fig. 18 is a horizontal section on the plane 1818 Fig. 17. s I

Referring to Figs. 1 to13;

The can bodies pass over the rotary disc formed on the surface ofthe table 81 by an.

inner fence 107 and an outer fence 108. The timing of the feed of canv bodies 72 iscontrolled by the star wheel 85.v A train of open top cans (or bottles) being suppliedto the table 81 is progressedv through the race by the rotatioi'ial.movement of the table;

The lingers of't'he star wheel 85 do not extend into the entering part of the race. But the race being eccentric to the star wheel: axis the star wheel lingers projectinto the latter portion. of. the raceway. Theleading canv (or bottle) in the train entering the race is crowded up against that one of the star wheel fingers which has sufliciently projected beyond. the inner fence of the race to obstruct its free movement through therace. As the st- 1: wheel fingers respectively pass that position the cans (or bottles) are taken in the bays between, its fingers and they are delivered into the machine whilst embraced (or bottle) is thus broughtinto the machinev in correct register and timin The, incom in bodies 72. aass successivel within ran 'e of the cruciform placerv wheel, 91, which is timed so. that one of its bays comes to position to embrace one side of the incomingcan body 72 as it is about to pass out of the race between the fences 107-108. The movement of the body forward upon the table. 8-1 is controlled by the rate of rotation of the placer wheel 91. and the body is moved forwardly whilst held by the placer wheel 9l and its distant side is caused to contact with. the fence 191 thence the bodies are traversed over the assembler table 109.

71 is atrigger finger mounted on. the top end of. a vertical rock spindle 69. This trigger finger is disposed to set normally in the end of the arm 68 takes behind a swinging.

latch jaw 63 which is pivotally mounted: at 163 in slotted aws in a Vertically oscillatable rod 60., So long asthe toe piece 168 bears inward against the'latch jaw 63 it holds it inward in the position shown in the full lines in Figs. 4 and 6, that is to say, in engagement with the clutch operating rod 51. This happens only whilst and so long as pressure is applied to the trigger 71 by a passing can body 72. l/Vhen a can body is not in contact with the trigger 71 the latch jaw 63 is forced to the disengaged position shown in dotted lines in Figs. 4 and 6 by means of the plunger 64 whichis acted upon by a spring 65, this spring being housed in a tubular casing 66 on the lower part of the rod 60. In the inner or engaged position which is shown in full lines, the latch 63 engages the check or hook 67 on the top end ofthe clutch operating rod 51. Only whilst the trigger 71 is pressed by a can body and the toe piece 168 thus forced inward and the mouthed latch 63 forced over to engagement position with the member 67 is it possible for reciprocating movement of the rod be communicated to the clutchoperating rod 51. The object of this arrangement is to procure engagement of the clutch to connect the drive to the cap feeder only whilst a can body is incoming to receive a cap from the cap feeder. 7 3 is a back stop which limits outward movement of the olfset cranked arm 68, and consequently limits the inner po sition of the trigger 71 whilst it is not being acted upon by a can body. Reciprocating movement is afpplied to the oscillator rod 60 by means 0 a cam 58 which is fixed on the top end of the clutch spindle 42. This spindle is maintained in constant rotation by the gear wheel from other parts of the machine.

59 is an anti-friction roller on an axle which is fixed in and offset laterally from the rod 60. This roller runs on the cam 58. The face of that cam is shaped to apply reciprocating movement in the required range and timing to the rod 60.

45 is a slide key of gnoinon shape housed in a key slot in the enlarged cylindrical portion 44 of the clutch spindle 42. 46 1s a spring housed in the same slot and functioning to force the broad portion of the key 45 out of the slot in the spindle. This enlarged portion of the spindle is housed for rotation in a hardened sleeve 48 which is secured by a key 49 concentrically in the clutch head/l1. The clutch head is integral with or is permanently attached to a gear wheel 40 which is in mesh with a spur gear 39. Through this gear drive motion is applied to the cap feeder from the spindle 42. 47 is a key slot in the sleeve 48 which is engageable by the clutch key When the clutch key is in the inner (declutched) position (see Figs. 10 and 13) there is no engagement between the spindle 42 and the clutch head 41. Conversely. when the key 45 is engaged to the clutch head, rotary motion is communicated to the wheel 39 through the pinion 40 from 60 topinvention, the liner is as its projecting the spindle 42 (which is in constant rotation). The key 45 is thus engaged with the key-way 47 whilst the clutch cap 50 is lifted (see 5) but is disengagedv when the clutch cap 50 is in the low position (Figs. 10 and 11). The clutch cap 50 is carried on the bottom end of the clutch operating rod 51 and a spring 53 housed in a casting 52 is. arranged to bear on the clutch cap 50 to force it downward. l/Vhen it is in the down position (see Figs. 10 and 11) it operates to force the key 45 inward and release the spindle 42 from the clutch head 41' and consequently to free the pinion 40. In the clutch the clutch cap is fitted with a segmental liner with a ramped end, in passing over which the clutch key is drawn, but in that case the clutch key is freed for reengagement as soon as it has run over the segment. In the arrangement of the present a ring with a slope sided notch in it, and for reengagement only when it is passing this notch whilst the The disengagement and reengagement of the clutch key is therefore effected only at one certain position in the rotational path of the clutch head. 54 is the hardened fixed bush or liner in the clutch caps; it is a free running fit on the spindle enlargement 44, and 56 is the slope formed in one side of it. This notch is of sufiicient dimensions to accommodate the 8X' tension portion of the key 45 and is shaped on the sides of 1t to present angular ramp faces to the sides of that key (see Fig. 12)

the keyis released clutch cap is lowered sided notch which is for the purpose hereinafter explained. The 1 clutch being engaged and the spring 53 operating to push down the cap 50, the bush 54 is caused to bear down on the projecting end of the key 45. When the mouth 56 in the bush 54 comes into register with the projectin end of the key 45 the cap slips down from the position shown in Fig. 5 to the position shown in Fig. 10. As the cap 50 is nonrotatable, the key 45 iscaused to be retired faces of the notch in the bush 54, and the key is consequently then forced inward to the position shown in F 10 so that the spindle 42 is thus disengaged from the pinion 40. It is held disengaged by engagement of its upper corner within the wall of the countersunk circularcup in its upper part of the mouthed ring When the cap 50 is again lifted the clutch key 45 will be re- *-leased and will fly out to the position shown,

in Fig. 5 and will then l e-engage the spindle 4.2 to the clutch head 41 as soon as it (the key) comes to register with the keyway 47 in-the clutch ring 48. The cap picks up the key to retire it only at the register position in which the notch in the bush is held. This clutch device ensures continuous operation of the machine whilst the feed is normal.

part runs over the angular So long as the toe piece 168 of the conmovement of the butter-plunger; Check pins trol mechanism is pressed inward, the latch 106 are fitted on thetop side of the gear jaw 63 will be held engaged with the head wheel 39. These pins clear the-butter casing, 67 of the clutch rod 51; consequently, the 104 in the rotation of the wheel 39.". A tree spindle 42 being in constant rotation and lever arm 101 is pivotally mounted on a pin maintaining the cam 58 in revolution, appli- 100 on theclutch cap 50. The back end of cation of reciprocating motion'irom the osthis; lever takes against a stop 10?. on-the' cillating head 60 to the clutch rod 51 and to capq50 and thelever 101 is fitted so that it the clutch cap 50 takes place. hen, howhastreedom for movement between thefull ever, the trigger 71 not pressed and conseline and the dotted line positions shown in 7 quently the toe 168 is in the free position Fig. 7 The buffer plunger 103- contacts.

and the latch jaw 63 is disengaged, the with the-back of the lever 101 and said lever clutch cap is not lifted by the rod 60 and is brought into; the path o1 the check pin the spring 53 acts to hold it down and main- 106 only when the clutchcap is lowered to 5 tain the key 45 disengagec. The cap feed the-position shown in Figs'10 and 11'. As 80 mechanism is driven through the gear wheel has been already explained, declutching is 39, and consequently when the clutch cap 50 effected when the: clutchcap is set down.

is'down, resulting from the trigger 71being' h it i 1; dQ n' n-e f th h k 106v free as shown in Fig. 1, driving motion, is makes contact with the lever 101 in the 0 no longer transmitted through t-he'pin-ion 40 course of the rotation of the wheel 39, and 35 to; the gear wheel'39' and thence to:- thecapthe motion thus applied to the lever 101 feed mechanism. is buffered by: the buffer-plunger 103 the re As soon asa can body makes contact with action of'the spring 105returning-thelever the trigger 71, forcing it outward from the 101' tothe full line position, thus bringing feed race, the toe piece 168- forcesin the the wheel 39'to stop with the check-106 lo- 99 latch 63. This latch then engages the head catedin; contact with; the side' oi" the-lever 67 of 'theclutch rod 51 at the bottom stroke 101 as seen dotted in Fig. 7. Rotation ofposition' of the rod 60. In the first upward the wheel 89" is thusal'ways arrested with movement eliected by the action of the cam one of the-checks 106 at one-certain position. 58, the clutch head 50 is lifted and the clutch- The number of checks 106' placed around 95 key 45 is then-free to engage the keyway 47.- the wheel 80 corresponds respectively with It is driven into the keyway 47 by the spring the numberotdeliv-eries effected bythe cap 46 as soon as it comes to register position feeder in each rotation of the spindle 88' therewith and the spindle 42 is thus engaged to which--thewheel 89-iskeyed. As the first to the clutch head 41 and consequently to the check-106 to arrive in contact-With the lever 100i pinion 40. The drive is then communicated 101 after the clutchhas been released corrcto'the cap'feed'er wl'iich-isca-usedtopertorm sponds with the position on the cap feeder a'movement in synchronismwith the body of the cap forthcomingtor delivery from feeder movement. Thus the action of the the; feeder onto theassembly table, that 40 cap feederis interrupted whenever there is forthcoming cap isyretained o'n the feeder, 1

not a body coming to receive thecap which asthefeeder. motion is arrested betore it is on its way to the assembly table, but the has brought the cap to the delivery posicap feeder is brought into action again imtion. When, as has been alreadyexplained, mediately a body comes to the appropriate the clutclris again engaged by the lifting position in relation to the waiting cap-at a ot'the cap- 50, the lever 101 is lifted up with later time in the rotation of the body feeder. the cap and so clears'the check- 106 which It is practically important that the arrest it had previously held engaged, then the ofmovement of the rotating members consewheel 39 and consequently the cap feeder quent on the clutch action shall not take is again free to be rotated and is automatr 50 place With great suddenness, and it-is necescallybrought into'rotation as soon as the 115 sary that they be broughtto stop at correct clutch has taken up the load. register positions and not permitted to ro- Referring now to the no lid, nocan type tate freely and stop at any accidental posimachine, Figs; 14 to'1'8. tion in the course of their rotation. There Substantially the same arrangement of is a certain momentum in the parts which mechanism is used in this converse case to 14) would cause their motion to continue after provide for the arrest otthe motionof the the clutch key 45 has been engaged. In or- "body feeder mechanism when any irreguder to take up this momentum and also to larity or stoppage occurs in the feed of buffer the stopping of the moving parts to caps. This is explained in 14 to 18 bring them to rest at correct register posiof the drawings, the corresponding parts tions, an automatic braking device is fitted. being numbered identically throughout. In A casing 104 carried on a bracket on the this case the trigger 71 is located in the path framing 43 carries in it a plunger buffer of the caps which are'beingmoved towards 103 which is backed by a helical spring 105, the receiving race in the machine by the cap- 3 a tail rod being fitted to limit the outward feeder (see Fig. 14)", and'the clutch mecha- V spindle nism is associated with the drive to the spindle 33 which actuates the body feeder, instead of, as in the previous case, being associated with the spindle 38 through which the cap feeder is driven.

lVhen the machine is started, motion is im parted to the toothed wheel 92 on the spindle 87. The gear wheel 92 on the spindle 87 conveys motion to the gear wheel 39 on the spindle 38 of the cap feeding mechanism, which takes caps one by one from the magazine 33 and advances them in single file to the take-off position for the assembly table. The gear wheel 93 gives motion to the gear wheel 75 on the spindle 42 and causes the slide rod 60 to be reciprocated. The can bodies 72 which are to receive caps 34 are fed as before described. The caps 34 pass the trigger 71 and through it the clutch 41 is controlled in the manner before described.

lVhilstthe feed is regular, the gear wheel is thus engaged to the spindle 42 and motion is transmitted to the gear wheels '96 and 97, which in turn rotates the gear wheels 77 and 84; the gear wheel 77 turns the hollow spindle 78 and the gear wheel 84 turns the 83 of the star wheel 85.

As the present invention is not concerned with the associated parts of the mechanism which relate to the structure of the machine parts other than the feeder, mechanical elements which are shown in the drawings to indicate the connection with those machine elements need not be described.

If the invention is being utilized in a machine in which cans (or bottles or other open containers) are filled with liquid or other product, then the first mentioned arrangement is used, the control being arranged for cutting off the feed of the product instead of arresting a cap feeder action. Any mechanical device may be utilized for this purpose which is dependent upon the rotation of the spindle 38 or a corresponding part for controlling a delivery valve. So long as the mechanism operates automatically to permit the spindle 38 or equivalent part to remain in rotation, the feed of product to the can bodies will not be arrested and the filling of the can bodies will then proceed uninter ruptedly subject to the usual feed control, which, as known in the art, includes means for opening a feed valve in proper timing to deliver product to a can which has reached the receiving position in the race and to stop the delivery before the can passes from that place, and in certain cases to retrieve the drip. The arrest of the rotation of the spindle 38 or equivalent part will in this arrangement operate to close a check valve or otherwise control the operation of the feed valve, so that when a can is missing from the train in the race the feed will be interrupted, but Will be re-established every time the latch mouth from the check 'ing a with it until the end of the downst'roke of the rod 51 as the bite of the undercut does not permit the latch to be released from the rod 51 by the action of the spring 65 until the tension on the spring 53 no longer operates and the latch is brought down in the downstroke of the rod so far7as to clear What I claim as my invention and desire to secure by Letters Patent is 1. Interlocking drive control means for machines in which a plurality of comple mentary operations is performed on stock fed into it, comprising a clutch in the drive transmission mechanism of one operative part of the machine; a control device for opening and closing said clutch; a trigger movable by contact with it of incoming stock whilst said stock is passing through the machine; mechanism associated with the trigger for tripping the clutch control device to close it when the trigger is moved by the stock, and to open it when the trigger is not so moved; and mechanism in the primary,

drive system of the machine for said control trip action.

2. Apparatus according to claim 1 wherein the trigger is fitted in a feed race and is moved to cause the closing of the clutch control mechanism only whilst incoming stock is making passing contact with it, and is reset by spring action to cause the opening of the clutch control mechanism at all other times.

3. Apparatus according to claim 1 in which the clutch control mechanism when closed is held closed for the period of one operation of the machine following the tripping action of the trigger mechanism.

' 4. Apparatus according to claim 1 includlatch on a constantly reciprocated member, a clutch control rod engageable by said latch, a spring arranged for effecting disengagement of said latch, and a member associated with the trigger and arranged to act against said spring to bring said latch into engagement with said trig er is moved by the contact with it of stock passing through the machine,

operating device obediently to the trigger a can comes to the charging position in the of the clutch op-' control when the Y engaging the latch from .said member,

"member carrying said :latch, the drlving mechanism for reciprocating reciprocating member,

5. Apparatus according to claim-1, adapted to a can-capping machine, wherein the nie'ans forlarresting the operation of the machine when-the "teed of stock is interrupted comprises a trigger in the stock race, a clutch control rod latch, a reciprocating and a cam in said member.

6. .The combination with a key clutch having-a capadapted todraw the key when it is set down and to "release the key for autoinatic engagement when it is ra1sed,-of a control rod carrying-the clutch cap, a check -on-said-- rod engageable with a complementary latch, thelat't'erlpivotally mounted on a .a cam on the clutch spindle and tappet on. said member meeting withit to applyreciprocating movement to said memberya-spring arranged for disand an arm on the'spindleof-ia trigger arranged for movingisaid latch against the spring to engage it with said member, substantially as described. v

7. Apparatus according to claim 6, including a"=bush in the clutch cap and a ramp with said. butler. said *cap is moved n ece, 326

sided notch cut in said bush, said notch being engageable with the clutch key to retire it and to release it thereby to cause opening or closing of the clutch respectively only whilst said hey 1S passing one certain posiiion in its revolution.

8. Apparatus according .to claim 6 in which the latch and engaging member checks are undercut with the object of maintaining'their engagement during the reciprocation o'fthe control-rod, substantially as described.

9. Apparatus according to claim 6 ineluding an attachment tor bringing: the lriven member of the clutch to a buffered stop at a predetermined position, said attachment comprising a stop on .a member which is rotated by the'clutch, a huiier carried on a fixed member and an arm carried pivotally on the clutch cap and coacting arm being: brought of thestop when the clutch to the positionin which disengagement ot-the :clutch takes place.

'In testimony whereof :he afiix'es his SYDNEY STUART.

into the path nature. 

